In present day machine tools, numerical controls are used to machine workpieces on the basis of an NC program. These NC programs are processed by the numerical control, which, for its part, controls the machine tool and initiates the necessary machining steps. These steps can include, for instance, choosing the tool, guiding the workpiece on a tool path, or switching on and off cooling agents. As machine tools become more and more efficient, NC programs are keeping pace with this development. For that reason, generating or editing an NC program constitutes an important step in the machining of workpieces using numerically controlled machine tools, and one that is requiring ever more outlay. Therefore, it is important to support the developer of such an NC program in the best way possible, so that he or she will be able to solve large and complex programming tasks efficiently and accurately.
To that end, European Published Patent Application No. 0 643 342 describes a method for generating and/or editing NC programs, which allows a structured representation of an NC program. For this, groups of syntax elements are combined into NC blocks and provided with comments. In a split screen display, an overall view of the NC program is then shown on the basis of the comments, and the complete NC program is also shown. The representation of the NC program itself, in which, after all, the NC program is entered or edited, is not further structured in the process, and the outlay required for generating or editing the program is increased by entering the comments. On the basis of the comments, an overview of the structure of the NC program may, in fact, be provided, but details are not made accessible.